, Volume 36, Issue 5, pp 458–462

Control of an Outbreak due to an Adamantane-Resistant Strain of Influenza A (H3N2) in a Chronic Care Facility


    • Chicago Dept. of Public Health
    • Centers for Disease Control and PreventionChicago Quarantine Station, AMC O’Hare, 66012
  • J. Y. Morita
    • Chicago Dept. of Public Health
  • D. K. Plate
    • Chicago Dept. of Public Health
  • R. C. Jones
    • Chicago Dept. of Public Health
  • M. T. Simon
    • Misericordia/Heart of Mercy Center
  • J. Nawrocki
    • Illinois Dept. of Public Health
  • A. M. Siston
    • Chicago Dept. of Public Health
  • S. I. Gerber
    • Chicago Dept. of Public Health
Brief Report

DOI: 10.1007/s15010-008-7295-9

Cite this article as:
Cohen, N.J., Morita, J.Y., Plate, D.K. et al. Infection (2008) 36: 458. doi:10.1007/s15010-008-7295-9



Chronic care facility residents are at risk of severe influenza infection and death. Adamantanes have been used by chronic care facilities for influenza A prophylaxis; however, genotypic resistance has altered prophylaxis recommendations. An outbreak of influenza A (H3N2) in a chronic care facility housing neurologically impaired children and young adults and subsequent control measures are described.

Patients and Methods:

Resident charts were retrospectively reviewed. Isolates were characterized by strain identification and pyrosequencing.


Although 95 (97%) of 98 residents had been immunized against influenza at the start of the influenza season, 16 (84%) of 19 case patients were identified on the first floor. However, following implementation of enhanced infection control practices and adamantane prophylaxis, only 10 (13%) of 79 case patients were identified on the second floor. Subsequent pyrosequencing studies revealed a serine to asparagine mutation at position 31 of the M2 protein.


Enhanced infection control precautions and adamantane prophylaxis were used to control spread of influenza in a chronic care facility. This outbreak demonstrates the importance of timely and consistent implementation of infection control measures in controlling influenza outbreaks in long term care facilities and raises questions about a possible role for adamantanes in preventing transmission of adamantane-resistant influenza A viruses.

Copyright information

© Springer 2008